Move store schema management operations to StoreSchemaHandler

We currently have an interface StoreSchemaHandler which was originally just aimed for RDBMS caching schema information. We should offload all other schema operations (create, delete, validate etc) to this to provide better separation of code between schema and runtime

Description

We currently have an interface StoreSchemaHandler which was originally just aimed for RDBMS caching schema information. We should offload all other schema operations (create, delete, validate etc) to this to provide better separation of code between schema and runtime